Good evening. As we come on the air, the republican national convention is finally under way. You can see it right there behind me. But it is still storm watch. And across the gulf coast, the front edge of isaac is now coming ashore. It is a category 1 hurricane, moving in on mississippi and louisiana. And the center is expected to make landfall at midnight. This now is isaac from space. Winds up to 80 miles per hour. 20 inches of unrelenting rain expected over the next three days. It could also spawn a swarm of tornadoes. In the dark of night. And we are tracking it all with cameras. And lake pontchartrain in new orleans, a road under water already as the water surges and have have live cameras showing preparation for a tough night on the beaches of gulfport, mississippi. And here is the weather warroom in tammany parish, abc's weather editor sam champion leading us off right now from new orleans. Sam. Good evening, diane from the mississippi river boat natchez, natchez will spend the night riding out in new orleans. That's the crescent city connection behind us that you can barely see in the early wind and rain bands ahead of isaac. So let's check with the very latest here. If there's any surprise in the track of last action of it, it's that this storm wants to spend a little more time slowing down just south of the delta of louisiana and maybe even curve a little bit more to the west, riding the coast. That slow path will mean more wind and more rain. And it will also spend an awful lot of time in america's heartland, dropping very heavy tropical rain in places that aren't used to seeing that action. Here's the path. Take a look at it. It's a little amazing as it goes from the gulf, past the border of st. Louis. That rain goes from atlanta and as far west as dallas. Now shas far as the winds go, this you may see a category 1 and think it's a small storm. But it's actually large in space storm. It ranges from 60 miles on either side of the center of the storm. And the tropical enforce winds about 180 miles an hour. There's an awful lot to this category 1 storm, diane. Okay. Sam. Thanks. From new orleans, we move to another city in the cross hairs, gulfport, mississippi and abc's meteorologist ginger zee is there. Ginger? Diane, it certainly isn't just new orleans, there is a 450-mile stretch of coastline along the gulf that tonight is in a tropical storm or hurricane warning. And that includes this city of gulfport. Look at the conditions behind me. The surf very rough. Deteriorating the last few hours. Already flooding on i-90 just east of biloxi, closing roads. Look at the video we got earlier, boarded up houses and buildings. Folks then getting offer the beaches. Police asking them to and tonight a mandatory curfew goes into place. Either way, the state of mississippi says, they're prepared. 1,500 national guard in place. At least 14 shelters open. Diane. Okay, thank you, ginger. Next, let's bring in abc's matt gutman, he's in mississippi where already it's knee-deep water on the ground. Matt. Diane, incredible, this is an island, beyond the pylons are the boat slips underneath the sheds there were picnic tables are now submerged. We're already looking at four to five feet of flooding. There's a mandatory evacuation for this marina, and all the communities south of here, folks along the gulf coast hunkering down. The worst concern is the water. It's going to continue to rise all night, diane.

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